The United States and Europe have spent the last week focused on Islamic State, but the possibility of conflict between China and Taiwan is far more dangerous to the world's security. An important development took place Nov. 7, when Chinese President Xi Jinping met for a historic summit with Taiwanese leader Ma Ying-jeou.

The meeting has been variously interpreted. But the best read is that it was a warning from China to Taiwanese voters not to move toward independence. That's particularly worrisome, because Ma's nationalist Kuomintang Party (KMT) is widely expected to lose upcoming elections to the independence-minded Democratic Progressive Party (DPP).

Although China and Taiwan have deep trade ties, this was the first public encounter between the leaders of the two countries since Mao Zedong and Chiang Kai-shek met for talks in 1945. It was therefore calculated on both sides to have maximum public effect. And it matters, in symbolic political terms at least, that Xi is the heir to Mao's leadership of the Communist Party while Ma is head of Chiang's KMT.